Display panel and manufacturing process thereof

ABSTRACT

The present disclosure provides a display panel and a manufacturing process of the display panel. The manufacturing process of the display panel includes: successively depositing a plurality of thin-film layers on an auxiliary electrode layer, the compactness of a single thin-film layer among the plurality of thin-film layers gradually increasing from bottom to top; forming a preset pattern by the plurality of thin-film layers having a same width; dry-etching the plurality of thin-film layers so that the width of a single thin-film layer among the plurality of thin-film layers gradually increases from bottom to top, to form a plurality of cathode separators having an inverted trapezoid shape. The manufacturing process of the cathode separator is highly stable.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Divisional Application of U.S. application Ser.No. 15/574,538 filed Nov. 16, 2017, which is the National Phaseapplication of International Application No. PCT/CN2017/109534 filedNov. 6, 2017, and claims the priority of Chinese Patent Application No.201710788449.2, filed on Sep. 5, 2017, in the State IntellectualProperty Office, the disclosure of which is hereby incorporated in itsentirety by reference herein.

BACKGROUND OF THE INVENTION Field of the Invention

The present disclosure relates to the technical field of displaytechnology, and more particularly to a display panel and a manufacturingprocess of the display panel.

Description of the Related Art

Existing display panels mainly include liquid crystal display (LCD)panels and OLED (organic light emitting diode) display panels. OLEDdisplay panels have been regarded as the most promising display panelsdue to their advantages of self-illumination, low driving voltage, highluminous efficiency, short response time, high definition and contrast,a viewing angle of approximately 180 degrees, wide available temperaturerange, the capability of flexible display and large-area full-colordisplay, and the like. With the improvement in processes andmanufacturing procedures of OLED display panels and the reduced cost,OLED TV sets have become more widespread and have been gradually knownand accepted by consumers.

Due to their superior display characteristics and quality than LCDs, forexample, lightweight, short response time, low driving voltage, betterdisplay color and display angle and the like, OLEDs have attractedextensive attention. In recent years, OLEDs develop dramatically. OLEDsmay be used for curved display and their development tends to large-sizeapplications. However, large-size applications will raise an IR dropissue, or even a Mura effect that is visible to the naked eyes.Therefore, technically, an auxiliary electrode and a plurality ofcathode separators are provided to separate cathodes of OLEDs so as tocontrol the cathodes separately. In this way, an effect of IR drop isreduced and the display quality is improved.

The conventional way of manufacturing a plurality of cathode separatorsis to form a plurality of cathode separators by applying an organicphotoresist, exposing and then developing, wherein an inverted-trapezoidshape of the cathode separator is formed by controlling processparameters, which leads to low stability.

SUMMARY OF THE INVENTION

An objective of the present disclosure is to provide a display panel anda manufacturing process of the display panel, in order to solve theexisting problem of low stability of the cathode separators.

For this purpose, the manufacturing process of the display panelprovided by the present disclosure adopts the following technicalsolution:

A manufacturing process of a display panel, comprising the followingsteps of:

providing a substrate layer;

forming a plurality of thin-film transistors on the substrate layer;

forming a planarization layer on the thin-film transistors;

forming an auxiliary electrode layer on the planarization layer;

successively depositing a plurality of thin-film layers on the auxiliaryelectrode layer by chemical vapor deposition, the compactness of asingle thin-film layer among the plurality of thin-film layers graduallyincreasing from bottom to top; the plurality of thin-film layerscomprise at least three thin-film layers, and a difference in thecompactness of adjacent thin-film layers among the plurality ofthin-film layers gradually increases from bottom to top;

applying a photoresist onto the plurality of thin-film layers, exposingand developing to form a preset pattern, the plurality of thin-filmlayers forming the preset pattern having a same width;

dry-etching the plurality of thin-film layers so that the width of asingle thin-film layer among the plurality of thin-film layers graduallyincreases from bottom to top; and

removing the photoresist applied onto the plurality of thin-film layersto form a plurality of cathode separators having an inverted trapezoidshape.

In the manufacturing process of a display panel of a preferredembodiment of the present disclosure, the step of successivelydepositing a plurality of thin-film layers on the auxiliary electrodelayer comprises:

passing into the equipment for many times, with one thin-film layerbeing deposited on the auxiliary electrode layer whenever passing intothe equipment.

In the manufacturing process of a display panel of a preferredembodiment of the present disclosure, the step of successivelydepositing a plurality of thin-film layers on the auxiliary electrodelayer comprises:

passing into the equipment once, with a plurality of thin-film layersbeing deposited on the auxiliary electrode layer in several steps.

In the manufacturing process of a display panel of a preferredembodiment of the present disclosure, one or more of SiN_(x), N₂, NH₃,TEOS, and N₂O is fed during the manufacturing process.

In the manufacturing process of a display panel of a preferredembodiment of the present disclosure, the auxiliary electrode is formedof one or more of ITO, Mo, Al, Ti, Cu, and alloys thereof.

In the manufacturing process of a display panel of a preferredembodiment of the present disclosure, the planarization layer is athin-film deposited by chemical vapor deposition.

A manufacturing process of a display panel, comprising the followingsteps of:

providing a substrate layer;

forming a plurality of thin-film transistors on the substrate layer;

forming a planarization layer on the thin-film transistors;

forming an auxiliary electrode layer on the planarization layer;

successively depositing a plurality of thin-film layers on the auxiliaryelectrode layer, the compactness of a single thin-film layer among theplurality of thin-film layers gradually increasing from bottom to top;

applying a photoresist onto the plurality of thin-film layers, exposingand developing to form a preset pattern, the plurality of thin-filmlayers forming the preset pattern having a same width;

dry-etching the plurality of thin-film layers so that the width of asingle thin-film layer among the plurality of thin-film layers graduallyincreases from bottom to top; and

removing the photoresist applied onto the plurality of thin-film layersto form a plurality of cathode separators having an inverted trapezoidshape.

In the manufacturing process of a display panel of a preferredembodiment of the present disclosure, the compactness of a singlethin-film layer among the plurality of thin-film layers graduallyincreasing from bottom to top comprises:

the plurality of thin-film layers comprise at least three thin-filmlayers, and a difference in the compactness of adjacent thin-film layersamong the plurality of thin-film layers gradually increases from bottomto top.

In the manufacturing process of a display panel of a preferredembodiment of the present disclosure, the compactness of a singlethin-film layer among the plurality of thin-film layers graduallyincreasing from bottom to top comprises:

the plurality of thin-film layers comprise at least three thin-filmlayers, and a difference in the compactness of adjacent thin-film layersamong the plurality of thin-film layers gradually decreases from bottomto top.

In the manufacturing process of a display panel of a preferredembodiment of the present disclosure, the step of successivelydepositing a plurality of thin-film layers on the auxiliary electrodelayer comprises:

successively depositing a plurality of thin-film layers on the auxiliaryelectrode layer by chemical vapor deposition.

In the manufacturing process of a display panel of a preferredembodiment of the present disclosure, the step of successivelydepositing a plurality of thin-film layers on the auxiliary electrodelayer comprises:

passing into the equipment for many times, with one thin-film layerbeing deposited on the auxiliary electrode layer whenever passing intothe equipment.

In the manufacturing process of a display panel of a preferredembodiment of the present disclosure, the step of successivelydepositing a plurality of thin-film layers on the auxiliary electrodelayer comprises:

passing into the equipment once, with a plurality of thin-film layersbeing deposited on the auxiliary electrode layer in several steps.

In the manufacturing process of a display panel of a preferredembodiment of the present disclosure, one or more of SiN_(x), N₂, NH₃,TEOS, and N₂O is fed during the manufacturing process.

In the manufacturing process of a display panel of a preferredembodiment of the present disclosure, the auxiliary electrode is formedof one or more of ITO, Mo, Al, Ti, Cu, and alloys thereof.

In the manufacturing process of a display panel of a preferredembodiment of the present disclosure, the planarization layer is athin-film deposited by chemical vapor deposition.

A display panel, comprising:

a substrate layer;

a plurality of thin-film transistors formed on the substrate layer;

a planarization layer formed on the thin-film transistors;

an auxiliary electrode layer formed on the planarization layer; and

a plurality of cathode separators formed on the auxiliary electrodelayer, each of the cathode separators comprising a plurality ofthin-film layers, the compactness of a single thin-film layer among theplurality of thin-film layers gradually increasing from bottom to top,the width of a single thin-film layer among the plurality of thin-filmlayers gradually increasing from bottom to top, the cathode separatorhaving an inverted trapezoid shape.

In the display panel of a preferred embodiment of the presentdisclosure, the plurality of thin-film layers comprise at least threethin-film layers, and a difference in the compactness of adjacentthin-film layers among the plurality of thin-film layers graduallyincreases from bottom to top.

In the display panel of a preferred embodiment of the presentdisclosure, the plurality of thin-film layers comprise at least threethin-film layers, and a difference in the compactness of adjacentthin-film layers among the plurality of thin-film layers graduallydecreases from bottom to top.

In the display panel of a preferred embodiment of the presentdisclosure, the auxiliary electrode is formed of one or more of ITO, Mo,Al, Ti, Cu, and alloys thereof.

In the display panel of a preferred embodiment of the presentdisclosure, the planarization layer is a thin-film deposited by chemicalvapor deposition.

Compared with the conventional technology, the advantage of the presentdisclosure is as follows: each of the cathode separators is formed by aplurality of thin-film layers having a different compactness. Thecompactness of the plurality of thin-film layers gradually increasesfrom bottom to top. Finally, dry-etching is performed. The cathodeseparators having an inverted trapezoid shape are formed due to thecharacteristics of the thin-films. The cathode separators formed in sucha way has the advantages of high stability of the manufacturing processand high patterning uniformity. The manufacturing process of a pluralityof cathode separators having an inverted trapezoid shape is simplified,and the efficiency is improved.

To make the contents of the present disclosure more apparent andunderstandable, the present disclosure will be described below in detailby preferred embodiments with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The technical solution, as well as beneficial advantages, of the presentdisclosure will be apparent from the following detailed description ofthe specific embodiments of the present disclosure, with reference tothe accompanying drawings.

FIG. 1 is a schematic view of the formation of a conventional cathodeseparator.

FIG. 2 is a flowchart of a manufacturing process of a display panelaccording to an embodiment of the present disclosure.

FIG. 3 is a schematic view of steps 1-3 for forming a plurality ofcathode separators according to an embodiment of the present disclosure.

FIG. 4 is a schematic view of steps 4-7 for forming a plurality ofcathode separators according to an embodiment of the present disclosure.

FIG. 5 is a schematic view of a display panel according to an embodimentof the present disclosure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

For better explaining the technical solution and the effect of thepresent disclosure, the present disclosure will be further described indetail with the accompanying drawings and the specific embodiments. Thedescribed embodiments are some but not all of the embodiments of thepresent disclosure. All other embodiments obtained by a person ofordinary skill in the art based on the embodiments of the presentdisclosure without creative efforts shall fall within the protectionscope of the present disclosure.

In the drawings, similar structural units are designated by the samereference numerals.

A display panel and a manufacturing process of the display panelaccording to an embodiment of the present disclosure will be describedbelow with reference to FIG. 1 to FIG. 5.

According to an embodiment of the present disclosure, as shown in FIGS.1 to 5, FIG. 1 is a schematic view of the formation of a conventionalcathode separator; FIG. 2 is a flowchart of a manufacturing process of adisplay panel according to an embodiment of the present disclosure; FIG.3 is a schematic view of steps 1-3 for forming a plurality of cathodeseparators according to an embodiment of the present disclosure; FIG. 4is a schematic view of steps 4-7 for forming a plurality of cathodeseparators according to an embodiment of the present disclosure; andFIG. 5 is a schematic view of a display panel according to an embodimentof the present disclosure.

As shown in FIG. 1, the manufacturing process of a conventional cathodeseparator comprises the following steps.

In the step 1, a substrate 110 is provided, on which a prepared TFTdevice (not shown) and an auxiliary electrode 120 are provided.

In the step 2, a layer of photoresist 130 is applied onto the auxiliaryelectrode 120.

In the step 3, the substrate applied with the photoresist 130 isexposed. In the step 4, the substrate is developed to form a pluralityof cathode separators 141 having an inverted trapezoid shape.

As shown in FIG. 2, an embodiment of the present disclosure discloses amanufacturing process of a display panel, comprising the following stepsS101-S108.

S101: A substrate layer is provided. The substrate layer may be a lowtemperature poly-silicon (LTPS) substrate. It may also be a glasssubstrate, a resin substrate or the like. It may also be an Oxide TFT orSPC or any TFT substrates.

S102: A plurality of thin-film transistors are formed on the substratelayer. A first metal layer is formed on the substrate layer, wherein thefirst metal layer comprises a plurality of gate lines; a firstinsulating layer is formed on the first metal layer; and a second metallayer is formed on the first insulating layer, wherein the second metallayer and the gate lines together form a plurality of thin-filmtransistors.

S103: A planarization layer is formed on the thin-film transistors. Theplanarization layer may be thin-film or PI material or a combination ofboth deposited by chemical vapor deposition (CVD).

S104: An auxiliary electrode layer is formed on the planarization layer.The auxiliary electrode may be made of metals such as Mo, Al, Ti and Cu,and alloys thereof, or may be made of ITO.

S105: A plurality of thin-film layers are successively deposited on theauxiliary electrode layer, the compactness of a single thin-film layeramong the plurality of thin-film layers gradually increasing from bottomto top. The plurality of thin-film layers may be successively depositedon the auxiliary electrode layer by chemical vapor deposition.

S106: A photoresist is applied onto the plurality of thin-film layers,exposed and developed to form a preset pattern, the plurality ofthin-film layers forming the preset pattern having a same width.

S107: The plurality of thin-film layers are dry-etched so that the widthof a single thin-film layer among the plurality of thin-film layersgradually increases from bottom to top.

S108: The photoresist applied onto the plurality of thin-film layers isremoved to form a plurality of cathode separators, wherein each of thecathode separators has an inverted trapezoid shape.

In the embodiment of the present disclosure, each of the cathodeseparators is formed by a plurality of thin-film layers having adifferent compactness. The compactness of the plurality of thin-filmlayers gradually increases from bottom to top. Finally, dry-etching isperformed. The cathode separators having an inverted trapezoid shape areformed due to the characteristics of the thin-films. The cathodeseparators formed in such a way has the advantages of high stability ofthe manufacturing process and high patterning uniformity. Themanufacturing process of a plurality of cathode separators having aninverted trapezoid shape is simplified, and the efficiency is improved.

Optionally, the compactness of a single thin-film layer among theplurality of thin-film layers gradually increasing from bottom to topspecifically comprises:

the plurality of thin-film layers comprise at least three thin-filmlayers, and a difference in the compactness of adjacent thin-film layersamong the plurality of thin-film layers gradually increases from bottomto top.

With such a design, a difference in the compactness of adjacentthin-film layers among the plurality of thin-film layers graduallyincreases from bottom to top. After the subsequent dry-etching, adifference in the width of adjacent thin-film layers graduallyincreases. That is, a difference in the width of a bottom base and thewidth of a top base of the inverted trapezoid shape gradually increases.The space occupied by the cathode separators becomes smaller. The spaceis saved.

Optionally, the compactness of a single thin-film layer among theplurality of thin-film layers gradually increasing from bottom to topspecifically comprises:

the plurality of thin-film layers comprise at least three thin-filmlayers, and a difference in the compactness of adjacent thin-film layersamong the plurality of thin-film layers gradually decreases from bottomto top.

With such a design, a difference in the compactness of adjacentthin-film layers among the plurality of thin-film layers graduallydecreases from bottom to top. After the subsequent dry-etching, adifference in the width of adjacent thin-film layers graduallydecreases. That is, a difference in the width of a bottom base and thewidth of a top base of the inverted trapezoid shape gradually decreases.The stability of the cathode separators becomes better. Cathodes ofOLEDs can be controlled separately by separating the cathodes using thecathode separators so that an elect of IR drop can be reduced. Thus, thedisplay problem is solved and the display quality is improved.

Further, one or more of SiN_(x), N₂, NH₃, TEOS, and N₂O is fed duringthe manufacturing process. This can ensure the stability during themanufacturing process and increase the success rate.

In some embodiments, the etching may be inductively coupled plasma (ICP)or enhanced cathode couple plasma mode (ECCP) or reactive ion etching(RIE) or any etching process.

In some embodiments, after forming a plurality of cathode separatorshaving an inverted trapezoid shape, a subsequent evaporation process iscontinuously performed. The subsequent evaporation process containsorganic material and a plurality of cathodes which are separated by thecathode separators.

Optionally, the step of successively depositing a plurality of thin-filmlayers on the auxiliary electrode layer comprises:

passing into the equipment for many times, with one thin-film layerbeing deposited on the auxiliary electrode layer whenever passing intothe equipment. The deposition effect will be better.

Optionally, the step of successively depositing a plurality of thin-filmlayers on the auxiliary electrode layer comprises:

passing into the equipment once, with a plurality of thin-film layersbeing deposited on the auxiliary electrode layer in several steps. Theoperation steps are simplified.

In some embodiments, in addition to the arrangement of the cathodeseparators on the auxiliary electrode layer, the cathode separators maybe arranged on a pixel define layer (PDL) or on a bank layer.

The manufacturing process of a display panel in accordance with thisimplementation may be applicable to a common display panel, and may alsobe applicable to AMOLED or UP techniques.

As shown in FIG. 3 and FIG. 4, the manufacturing process of the cathodeseparators in this embodiment comprises the following steps.

In the step 1, a substrate 111 is provided, on which a prepared TFTdevice (not shown) and an auxiliary electrode 121 are provided.

In the step 2, a CVD thin-film 140 is deposited on the auxiliaryelectrode 121. The CVD thin-film 140 is deposited for many times andbecomes more compact from bottom to top.

In the step 3, a photoresist 131 is applied onto the CVD thin-film 140and the CVD thin-film 140 is then exposed.

In the step 4, the CVD thin-film 140 is developed to form an image.

In the step 5, dry-etching is performed to remove the CVD thin-film 140exposed from the photoresist.

In the step 6, after the dry-etching, since the CVD thin-film 140gradually loosens from top to bottom, a plurality of separators 131, 141having an inverted trapezoid shape are formed.

In the step 7, after the photoresist is peeled off, the cathodeseparators 141 formed of the CVD thin-film are formed.

As shown in FIG. 5, an embodiment of the present disclosure furtherdiscloses a display panel comprising a substrate layer 111, a pluralityof thin-film transistors, a planarization layer 171, an auxiliaryelectrode layer 121 and a plurality of cathode separators 141.

The substrate layer may be a low temperature (LTPS) substrate. It may bea glass substrate, a resin substrate or the like. It may also be anOxide TFT or SPC or any TFT substrates. The thin-film transistors areformed on the substrate layer.

The planarization layer 171 is formed on the thin-film transistors. Theplanarization layer 171 may be thin-film or PI material or a combinationof both deposited by chemical vapor deposition (CVD).

The auxiliary electrode layer 121 is formed on the planarization layer.The auxiliary electrode 121 may be made of metals such as Mo, Al, Ti andCu, and alloys thereof, or may be made of ITO.

The cathode separators 141 are formed on the auxiliary electrode layer121. Each of the cathode separators 141 comprises a plurality ofthin-film layers. The compactness of a single thin-film layer 140 amongthe plurality of thin-film layers gradually increases from bottom totop, and the width of a single thin-film layer 140 among the pluralityof thin-film layers gradually increases from bottom to top. Each of thecathode separators 141 has an inverted trapezoid shape.

In this embodiment of the present disclosure, each of the cathodeseparators 141 is formed by a plurality of thin-film layers 140 having adifferent compactness. The compactness of the plurality of thin-filmlayers gradually increases from bottom to top. Finally, dry-etching isperformed. The cathode separators each having an inverted trapezoidshape are formed due to the characteristics of the thin-films. Thecathode separators formed in such a way have the advantages of highstability of the manufacturing process and high patterning uniformity.The manufacturing process of a plurality of cathode separators having aninverted trapezoid shape is simplified, and the efficiency is improved.

Optionally, the plurality of thin-film layers comprise at least threethin-film layers, and a difference in the compactness of adjacentthin-film layers among the plurality of thin-film layers graduallyincreases from bottom to top.

With such a design, a difference in the compactness of adjacentthin-film layers among the plurality of thin-film layers graduallyincreases from bottom to top. After the subsequent dry-etching, adifference in the width of adjacent thin-film layers graduallyincreases. That is, a difference in the width of a bottom base and thewidth of a top base of the inverted trapezoid shape gradually increases.The space occupied by the cathode separators becomes smaller. The spaceis saved.

Optionally the plurality of thin-film layers comprise at least threethin-film layers, and a difference in the compactness of adjacentthin-film layers among the plurality of thin-film layers graduallydecreases from bottom to top.

With such a design, a difference in the compactness of adjacentthin-film layers among the plurality of thin-film layers graduallydecreases from bottom to top. After the subsequent dry-etching, adifference in the width of adjacent thin-film layers graduallydecreases. That is, a difference in the width of a bottom base and thewidth of a top base of the inverted trapezoid shape gradually decreases.The stability of the cathode separators becomes better. The cathodes canbe controlled separately by separating the cathodes so that an effect ofIR drop can be reduced. Thus, the display problem is solved and thedisplay quality is improved.

In some embodiments, in addition to the arrangement of the cathodeseparators 141 on the auxiliary electrode layer 121, the cathodeseparators 141 may be arranged on a pixel define layer (PDL) 181 or on abank layer.

The display panel may further comprise a first insulating layer 151, afirst metal layer and a second insulating layer 161.

The first insulating layer 151 is arranged on the substrate 111. Thefirst metal layer is arranged on the first insulating layer 151 andcomprises a gate line 191, 194. The second insulating layer 161 isarranged on the first metal layer.

Although the present disclosure has been described with reference to thepreferred embodiment thereof, it is apparent to those skilled in the artthat a variety of modifications and changes may be made withoutdeparting from the scope of the present disclosure which is intended tobe defined by the appended claims.

What is claimed is:
 1. A display panel, comprising: a substrate layer; aplurality of thin-film transistors formed on the substrate layer; aplanarization layer formed on the thin-film transistors; an auxiliaryelectrode layer formed on the planarization layer; and a plurality ofcathode separators formed on the auxiliary electrode layer, each of thecathode separators comprising a plurality of thin-film layers, thecompactness of a single thin-film layer among the plurality of thin-filmlayers gradually increasing from bottom to top, the width of a singlethin-film layer among the plurality of thin-film layers graduallyincreasing from bottom to top, each of the cathode separator having aninverted trapezoid shape.
 2. The display panel as claimed in claim 1,wherein the plurality of thin-film layers comprise at least threethin-film layers, and a difference in the compactness of adjacentthin-film layers among the plurality of thin-film layers graduallyincreases from bottom to top.
 3. The display panel as claimed in claim1, wherein the plurality of thin-film layers comprise at least threethin-film layers, and a difference in the compactness of adjacentthin-film layers among the plurality of thin-film layers graduallydecreases from bottom to top.
 4. The display panel as claimed in claim1, wherein the auxiliary electrode is formed of one or more of ITO, Mo,Al, Ti, Cu, and alloys thereof.
 5. The display panel as claimed in claim1, wherein the planarization layer is a thin-film deposited by chemicalvapor deposition.